I am still working on my friends M37. Corrected the ground back from + to – ground. The truck still has very weak spark. It is a weak yellow look.
So I decided it was time to replace the wiring as I think it is just shot and causing problems. He bought a wiring kit from Vintage Wiring of Maine. It took a while to pull the old stiff crusty wire out. That new harness was great. I got all the wire run and most of the connections done it an evening. Once I get everything connected or taped up I will check the spark again and see if she runs. If not I guess the next thing is a possible weak coil.
Personally, if it was me, I would only wire up what is required for the ignition and engine to run first.
That way you wont have any other possible electrical problems to contend with.
Once you have solved the ignition problem you can go ahead and wire everything else up.
Cheers
Stu
Stu
1952 Dodge M37 with 1952 M101 Trailer
MVT UK
SMVG Scotland
Went to the auto parts store and asked for a condenser. After two of them had to search through their on line system for awhile. They finally found one.
Got home and installed it in the distributor and now there is a better spark. The engine will at least cuff now. It still won't start. What are the symptoms of a weak coil?
Yep. All new wire all through out the truck. Even the gas gauge works now.
I took the distributor cover off with the switch on and there was 24volts on the + of the coil. The points have .020 gap. I turned the engine to Top Dead Center and moved the distributor to point to the #1 spark plug. Put the cover back on and with the new condenser it will try to start but not just not go faster than the starter. I am thinking the new condenser is helping compensate for a weak coil. The guy has a new coil but I will not get it from him until Sat.
As my friend said getting to Top Dead Center and pointing the rotor to #1 it should run. Might run crappy but should run.
Next if the coil does not fix it then I am thinking carburetor but that was recently rebuilt and the truck was running two weeks ago and we smell gas coming out of the exhaust. It could be flooding though so one of the things I try when starting it is holding the gas pedal all the way down. Once the gas from the accelerator pump is gone having the butterfly wide open will allow the engine to pump out any excess gas.
It isnt uncommon in a situation where you are cranking a long time without it starting for spark plugs to get fuel soaked and then not fire. I would pull them, and if you have a sandblast cabinet, blast the electrode ans porcelain areas. I dont think just wiping or blowing them off will do it.
Tim
Interesting that you say clean the spark plugs because before the spark died I did take them out and scrub them with a brass brush. After putting them back in the engine it did try to start a few times better than now. So I will try bead blasting them. One thing I know is this truck floods easy. I will report back.
First of all a digital VOM is needed for best, most reliable and accurate readings. You are looking for .5 to 1.0 Ohms across the primary coil. Zero indicates the primary coil is shorted. Infinity or open means the coil has a broken wire. The secondary will ohm out anywhere from 14,000 to 20,000 ohms.
cuz wrote:Have you ohmed out both the primary and secondary side of the coil both cold and hot? Or have you computed or measured the current draw of the coil?
Wes, How do you ohm your coil, can you splain it to me/us?
Well I tested the coil and across the primary it tested 1 Ohm and across the secondary it tested 10,000 Ohms. I am not sure if that means it is weak or not.
Once I got the idea of blasting the spark plugs it reminded me of the old days when my Dad used to take his spark plugs up to the local service station to get his blasted in one of the spark plug machines. Now we see those machines on that Pickers show. Man does that make me feel old.
After I did a light bead blasting of the plugs and installed them back the truck started on the first push of the starter plunger without touching the gas pedal and no choke! I then timed using an adapter and a light since I had already cleaned the pulley and marked TDC and the pointer in white. Now it runs great.
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